GENERIC CLASSIFICATION OF APHIDIDAE. 79 



closely related. The other characters mentioned by Theobald are 

 seen to be present in the type species. The tubercles he figures and 

 describes are the same and the spines on the first and second antennal 

 segments are evidently the thickened, pointed, chitinized articula- 

 tions of the segments common in insects of this type. We believe, 

 therefore, that Rectinasus should be carried as a synonym of Forda. 

 Westwood's genus was erected on his betae which appears to belong 

 here as recently indicated by the writer. 



Characters. — Cornicles wanting; apterous forms with five-segmented antennse and 

 eyes of three facets. Alate form with five-segmented antennae and medium-sized 

 oval, or more or less irregularly shaped sensoria. Fore wings with media simple; 

 hind wings with both media and cubitus present, arising slightly apart. Subterranean 

 forms living usually in the nests of ants and tended by them. 



Type (monotypical), Forda formicaria Heyden. 



Genus GEOICA Hart. 



Plate XIV, A-K. 



1894. Geoica Hart, 18th Rept. State Ent. 111., p. 101. 



1860. Tychea Passerini, Gli Afidi, p. 30. 



1906. Tycheoides Schouteden, Mem. Soc. Ent. Belg., v. 12, p. 194. 



1906. Kaltenbadiiella Schouteden, Mem. Soc. Ent. Belg., v. 12, p. 194. 



1909. Trifidaphis Del Guercio, Rivista Patol. Vegetale, n. s., v. 3, p. 332. 



1912. Tullgrenia V. d. Goot, Tijdschr. voor Ent., v. 15, p. 96. 



1913. Trinacriella Del Guercio, Redia, v. 9, p. 169. 



1916. Serrataphis V. d. Goot, Zur Kenntniss der Blattlause Java's, p. 263. 



In 1860 Passerini used the generic name Tychea of Koch and placed 

 as the typical species pTiaseoli Pass. In 1863 he used the name 

 again, listing several species but not the species included by Koch. 

 Therefore his interpretation of the genus can not be correct. In 1894 

 Hart erected his genus Geoica with squamosa as type. In 1906 

 Schouteden noticed Passerini 's mistake and suggested the name 

 Tycheoides but made eragrostidis Pass, the type. In the same year 

 he erected Kaltenbachiella with menthae Schout. as type. In the 

 year 1909 Del Guercio erected Trifidaphis with radicicola Essig as 

 type. In 1912 Van der Goot noted Passerini's mistake and proposed 

 the name Tullgrenia for the Tychea of Passerini. In 1916 Van der 

 Goot erected the genus Serrataphis with lucifuga Zehntner as type. 



In studying cotypes and other specimens of squamosa certain 

 generic characters are evident. The species is subterranean. It has 

 five-segmented antennse in the apterous form and six-segmented ones 

 in the alate. It is true, however, that the apterous form sometimes 

 has only four segments in the antennas and the alate five. 

 Indeed, in some alate forms there is a five-segmented antenna on one 

 side and a six-segmented one on the other. One of these five- 

 segmented antennas was figured by Hart. One wing vein only was 

 figured in the hind wing by Hart, but a very close examination shows 

 that both the media and cubitus, though faint, are present. These 

 are very difficult to trace in balsam mounts. In giving his name 



